1. Field
Embodiments of the inventive concept relate to a radar cross section reflector for indicating an emergency position.
2. Description of Related Art
Safety Of Life At Sea (SOLAS) proposes that a radar cross section (RCS) for recognizing an object on the sea should be 10 m2 and obligates that the RCS should be equipped in vessels so as to prevent a clash between small and large vessels.
An RCS is proposed with its verified result for a typical radar reflector and can be largely extended in a multi-hedral structure such as a di-hedral or tri-hedral structure.
FIG. 11 shows a basic theory about the RCS. According to the theory, it can be seen that in a radar reflector on which a di-hedral or tri-hedral metal films, a tri-hedral radar reflector having one side of 1 for a radar wave of a conventional 3 GHz band is equipped with an RCS over 3500 times of a spherical metal reflective surface having a radius of 1 and even over 3 times of a planar metal reflective surface.
Therefore, when there is emergency at sea, utilizing the characteristics of such a radar reflector helps a victim to effectively indicate his emergency position to a vessel or relief squad, which is passing by, by means of the radar reflector.
With regard to this view, the present applicant made the application (Application No. 10-2008-0050410) at May 29, 2008, entitled “Emergency position indicating device using RCS (Radar Cross Section) characteristics” (hereinafter referred to as ‘related art’), which was issued for patent at Dec. 2, 2010 (Patent No. 10-0999442) (see FIG. 12).
The related art is provided to solve a problem that makes it difficult to find a victim's position when there is an emergency on the sea. According to the related art, it is possible to quickly find an emergency position in the daytime or nighttime regardless of marine environments, overcoming the shortness arising from an Emergency Position Indicating Radio Beacon (EPIRB) that operates a large error bound of 4 mile and a cyalume lightstick limited in indication range. Referring to the related art, to effectively indicate an emergency position, radar emitted from a vessel or relief squad passing by the emergency position is intensively reflected on a balloon-type device embedding a radar reflector on which a di-hedral or tri-hedral metal film is covered to maximize an RCS, or on a self-floating radar reflector, while the device or the self-floating reflector is floating for a long time over the emergency position in a sufficient height 10˜30 m after injecting a gas, which is lighter than air, thereinto.
While the related art, operable by attaching an EPIRB, which includes a radar reflector, to a life jacket, is theoretically capable of indicating an emergency position in the daytime or nighttime regardless of marine environments, there would be inconvenience or limits as follows in operation for actual emergency on the sea.
First, in an actual case of emergency on the sea, victims are usually dropped into seawater without wearing life jackets beforehand. Since most victims are incapable of swimming, the utility of the related art would be lower.
Second, if seawater temperature is low, a victim's consciousness rapidly goes down and senses of fingers, arms and legs dull to cause their movement to be hard. As a result, it would be difficult to operate a device of the related art for indicating his emergency position.
Third, the lack of means for safely operating a device of the related art would cause a victim to be damaged if the device malfunctions in emergency. And, if some important components of the device of the related art get out of order, it cannot be used.
Fourth, while a radar reflector needs to be floated over an appropriate height for providing a proper reflection section and securing distant recognition, the device of the related art may be floated lower than a desired height due to wind.